HoverBall: augmented sports with a flying ball. - Kei Nitta; Keita Higuchi; Jun Rekimoto (AH, 2014)

PhotoelasticBall: a touch detectable ball using photoelasticity. - Kei Nitta; Toshiki Sato; Hideki Koike; Takuya Nojima (AH, 2014)

Shepherd pass: ability tuning for augmented sports using ball-shaped quadcopter. - Kei Nitta; Keita Higuchi; Yuichi Tadokoro; Jun Rekimoto (Advances in Computer Entertainment, 2015)

Generating Spherical Hyperlapse Videos via Recursive Intelligent Sampling for StratoJump. - Keita Higuchi; Shunichi Kasahara; Kei Nitta; Yohei Yanase (ISS, 2018)